Report

Hydrologic Regulation of Chemical Weathering and the Geologic Carbon Cycle

+ See all authors and affiliations

Science  13 Mar 2014:
1250770
DOI: 10.1126/science.1250770

You are currently viewing the abstract.

View Full Text

Abstract

Earth’s temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks that operates over million-year time scales. To explain variations in the strength of the weathering feedback, we present a model for silicate weathering that regulates climatic and tectonic forcing through hydrologic processes, and imposes a thermodynamic limit to weathering fluxes based on the physical and chemical properties of the river basin. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts, even in the absence of appreciable changes in CO2 degassing rates.

View Full Text